Offsetting Arrangements (Assets With Offsetting Arrangements) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	$ 8,376		$ 11,977	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	(4,907)	[2]	(6,501)	[2]
Net Amounts of Assets Presented in Statement of Condition	3,469		5,476
Resale Agreements and Securities Borrowing, Gross Amounts of Recognized Assets	47,715	[3]	48,221	[1],[3]
Resale Agreements and Securities Borrowing, Gross Amounts Offset in Statement of Condition	(30,307)	[2],[3]	(30,700)	[2],[3]
Net Amounts of Assets Presented in Statement of Condition	17,408	[3]	17,521	[3]
Total, Gross Amounts of Recognized Assets	56,091		60,198	[1]
Total, Gross Amounts Offset in Statement of Condition	(35,214)	[2]	(37,201)	[2]
Total, Net Amounts of Assets Presented in Statement of Condition	20,877		22,997
Securities purchased under resale agreements	6,087		6,230
Securities borrowed subject to master netting arrangements	11,321		11,291
Cash collateral netting
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	0		0	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	(1,372)	[2]	(1,928)	[2]
Net Amounts of Assets Presented in Statement of Condition	(1,372)		(1,928)
Interest-rate contracts
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	56		65	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	(45)	[2]	(59)	[2]
Net Amounts of Assets Presented in Statement of Condition	11		6
Foreign exchange contracts
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	8,318		11,911	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	(3,489)	[2]	(4,514)	[2]
Net Amounts of Assets Presented in Statement of Condition	4,829		7,397
Other derivative contracts
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	2		1
Derivatives, Gross Amounts Offset in Statement of Condition	(1)		0
Net Amounts of Assets Presented in Statement of Condition	$ 1		$ 1

[1] Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.

[2] Amounts subject to netting arrangements which have been determined to be legally enforceable.

[3] Included in the $17,408 million as of March 31, 2014 was $6,087 million of resale agreements and $11,321 million of collateral provided related to securities borrowing. Included in the $17,521 million as of December 31, 2013 was $6,230 million of resale agreements and $11,291 million of collateral provided related to securities borrowing. Resale agreements and collateral provided related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Refer to note 7 for additional information with respect to principal securities finance transactions.